The Sennheiser PXC 350 is a pair of closed, around-the-ear headphones designed for premium-grade noise cancellation meant to challenge its Bose Quiet Comfort series competitors. Using NoiseGard Advance technology, the headphones reduce ambient noise by up to 85%. Also featured is a foldable design for easy storage, in-line volume controls, and two AAA batteries for achieving optimal noise cancellation. Overall, critics and consumers alike agree that the Sennheiser PXC 350 provides premium noise isolation with a crisp high-frequency response. However, customers seeking added bass would be better off with an open-backed design.